troubles with 99 yz400f

burelybean

I have a 99 yz400f, the bike is overheating within a minute or two of initial startup. When riding the bike loses all tourge and has just enough to pull the bike. Have not the slightest step to take next any ideas would be appreciated

tom nolan

If the bottom of the radiators are cooler than the top when the bike is standing still and idling, than the water pump impeller is not turning. You should be able to see the fluid moving across the top of the right radiator with the cap off.